1. Field of the Invention
The present invention relates to electrical connectors. In particular it relates to devices especially appropriate for accomplishing electrical connection between a multi-layer (or printed circuit) board and a master interconnect board.
2. Description of the Prior Art
Electrical connector apparatus and methods in present technology continually encounter design and concept problems related to the progressive miniaturization of electrical components. A commonly encountered situation involves the connection of a multitude of multi-layer, also known as printed circuit, boards to a master interconnect board. Applications may arise in computers, missiles, memory systems or any number of sophisticated present day electronic systems. It is often necessary and desirable to achieve compact design of the master interconnect board, thereby minimizing the area into which the multi-layer boards must be "ganged".
The efficient utilization of the many inputs afforded by a master interconnect board often time dictates that a very dense contact pin array join the individual multi-layer boards to the master interconnect board. Also, a 90.degree. or edge to surface relationship between the multi-layer and master interconnect boards often proves quite space saving. Efficient design may be hampered if the inherent physical materials and stability limitations of the contact pins and attendant manufacturing processes are not solved.
Previous methods in the area of the present invention were hampered by designs which provided high insertion force stresses to the delicate pin contacts, making blind insertion and close location impossible to achieve. Additionally, prior designs did not provide access to the individual pins so that a partially-defective connection could be partially unsoldered and thus salvaged. An additional failure of the prior art was the inability of the pins to be simply retained in position during critical joinder processes such as the application of wave soldering techniques to secure the pins to multi-layer boards. Often complex supplemental equipment was employed to achieve critical stability. See, for example, Shultz, U.S. Pat. No. 3,800,416.
The present invention solves this and other problems by means of a connector header of unique design which allows access to individual pins for unsoldering joined to a lead-in header which guides the pins so they may encounter zero insertion force when mated into the master interconnect board. A dimple is provided on each contact pin for retention in the connector assembly during soldering or other attachment processes.